CodeRush - DevExpress CodeRush for Roslyn uses significantly less memory, works faster, and lets you start Visual Studio faster.
ReSharper - ReSharper is a productivity tool for visual studio that provides tools and features to help you manage your code.
ReSharper C++ - ReSharper provides on-the-fly code analysis and eliminates errors in C#, VB.NET, XAML, ASP.NET, and XML
NDepend - NDepend is a Visual Studio tool to manage complex .NET code and achieve high code quality.
TestDriven.NET - TestDriven.Net makes it easy to run unit tests with a single click, anywhere in your Visual Studio...
Klocwork - Klocwork is a static code analysis and SAST tool for C, C++, C#, Java, and JavaScript.